Surface adsorption of methyl blue promotes the electrocatalytic hydrogen evolution on the composite of platinum and...

Electrocatalytic hydrogen evolution reaction (HER) is a promising way to produce clean hydrogen energy. Although a variety of strategies have been developed to improve the performance of HER, it is still necessary to further develop cost-effective and efficient method for further improvement of HER performance. In this work, we proposed a novel method to further improve the HER performance of platinum (Pt) by adsorbing carefully chosen molecules on the composite of Pt and reduced graphene oxide (rGO). Typically, the molecules of methyl blue (MB) were selectively adsorbed on the surface of rGO sheets. The adsorption of MB molecules could promote interfacial charge transfer, leading to an improvement in electrocatalytic HER. After the adsorption of MB, the output current density at -0.6 V vs. RHE increased for 1.5 folds to 195 mA cm^-2, and the overpotential at 10 mA cm^-2 decreased from -0.109 to -0.084 V vs. RHE. The improved charge transfer at interface was verified with many electrochemical measurements and theoretical calculations. Overall, this work proposes a simple and effective method to improve the electrocatalytic performance of HER, and this method could be easily and conveniently applied to many other catalytic systems.